1. Field of the Invention
The present invention relates generally to the manufacture of precision electronic and mechanical components, and more specifically to apparatus used in processing semiconductor integrated circuits, modules, hard disk drive components and media, and biomedical devices and apparatus that rinse and dry such components after chemical processing or cleaning.
2. Description of the Prior Art
A common process used more than once and throughout the manufacture of semiconductor integrated circuits, multi-chip modules, and hard-disk magnetic media, is the rinsing and drying of such components after each step of the chemical processing steps. Typically, the rinse must be capable of removing ionic contamination and the devices must be dried residue-free. The object of rinsing and drying is to remove contamination. Thus, a rinsing or drying step that adds particulates or other contaminates is unacceptable.
Presently, the spin rinse dryer is widely used in the industry. In this system, the devices to be rinsed and dried are spun on their axes, or placed on a rotor and spun around the rotor axis. The devices are then typically sprayed with high-purity, deionized (DI) water. This is followed by spinning in a heated atmosphere of high purity nitrogen. The drying rate is accelerated by the combination of centrifugal force that throws the water rinse off the device and evaporation. Although the spin-rinse dryer has been improved over the years, it nevertheless has a number of shortcomings which have been exacerbated by the ever decreasing geometries appearing in state-of-the-art electronic devices. Spin-rinse dryers can actually generate particulates, due to their rotating parts. Extraordinary measures must be taken to eliminate these generated particles from processing systems. Spin-rinse dryers also require a tooling change for changes in component sizes or shapes. The residue-free drying performance of spin-rinse systems is highly dependent on the maintenance attention given to the machine and the quality of the incoming water.
A number of alternative methods have been introduced, each with its own set of new problems. The most common of these alternative methods is the alcohol dryer, which does not provide a rinse to remove ionic contaminates. The alcohol dryer works by displacing water with alcohol through the condensation of hot alcohol vapor on a device surface. The drying then depends on evaporation of the condensed alcohol. A major issue with alcohol dryers is safety. One particular system on the market has resorted to the use of seventeen different safety interlocks to make the unit safe. The reliability of such a dryer is in doubt because the complexity invites failures. A similar dryer has been marketed that uses an exotic, albeit expensive chemical that is much less hazardous than alcohol. Beyond the obvious increase in costs, the effects of the exotic chemicals on devices being processed are not yet completely understood.
Another alternative to the spin-rinse dryer is the meniscus dryer, which pulls devices very slowly from hot high-purity DI water, and relies on surface tension to wick-off substantially all of the water from the device. The remaining water is easily evaporated away. The successful operation of this system is highly dependent on the size and shape of the devices being processed. It may not be a solution in all cases and can be hard to control in production environments. The corrosive effects of hot DI water used in this dryer are a source of new problems that must be addressed.
Therefore, an improvement in rinsing and drying technology is needed. The present invention overcomes the problems traditionally associated with rinsing and drying.